The objectives of this study were to determine the chemical composition and to evaluate the mosquito repellent property of essential oils extracted from the bark of the stem of Sterculia tragacantha Lindl on Anopheles gambiae, vector of malaria. The essential oil of the stem bark of S. tragacantha Lindl is extracted by hydrodistillation and their chemical compositions were identified by GC (Ir) and GC-MS. This oil has been tested on sensitive « kisumu » strains of A. gambiae adults, according to the World Health Organization (WHO) guidelines for laboratory testing of the repellency of chemicals. The extraction yield obtained from this oil is 0.12%. By means of GC (Ir) and GC-MS, 29 compounds representing 88.4% of the HE were identified. β-elemol (40.54%) is the major compound of this oil. It is rich in sesquiterpenes (79.47%) with a predominance of oxygenated sesquiterpenes (55.86%). As for the oxygenated monoterpenes, they represent 8.93%. The repellency test against adult female Anopheles, revealed that the EO of S. tragacantha (10%) has repellent properties against mosquitoes. Indeed, it induces an average reduction of 98.2% of the blood meal (TIRS) of mosquitoes on guinea pigs with a complete protection time (CPT) of 5 h compared to 3 h 30 min for the natural reference substance (Cymbopogon citratus). In view of its extractive value and prolonged repellent properties, S. tragacantha could be a good alternative in the vector borne diseases control if used as natural repellents for skin application.

Objective: This research aims to evaluate the antibacterial activity and determine the chemical composition of the aqueous extract of the bark of Lannea barteri Engl. (DA) used in the traditional treatment of urinary tract infections in the Ivory Coast.Methods: The material is composed of DA, the bacterial strains of Pseudomonas aeruginosa and Acinetobacter baumannii, isolated from the urine of patients from different hospitals and subsequently stored. The qualitative analysis was performed using color-based detection tests and thin layer chromatography (TLC) reactions and the quantification of total phenols, flavonoids, flavone aglycones and anthocyanins using the method of Folin Ciocalteu. The method of diffusion on Mueller Hinton (MH) agar medium has been used for sensitivity tests. Results: The phytochemical screening of DA has revealed the presence of polyphenols, terpenes, and derivatives, coumarins, tannins, flavonoids, and alkaloids. Furthermore, the quantification of some polyphenols such as flavonoids, flavone aglycones, and anthocyanins was determined. The total polyphenols found was 0.757±0.003 mg/g MS representing respectively; 0.230±0.01 for flavonoids; 0.028±0.02 for flavone aglycones and 0.016±0.02 mg/g MS for anthocyanins. DA is bactericidal against Pseudomonas aeruginosa and Acinetobacter baumannii, which are mainly responsible for urinary tract infections.Conclusion: The bark of Lannea barteri Engl. (DA) is rich in flavonoids, flavone aglycones, and anthocyanins which are probably responsible for its antibacterial properties on Pseudomonas aeruginosa and Acinetobacter baumannii. This research thereby supports the use of this plant in the treatment of urinary tract infections.

This study aimed to analyse the chemical composition of essential oils from Diphasia klaineana fruits, its fractions and evaluate their antibacterial activity. The GC-MS analysis and agar disc diffusion and microbroth dilution methods were carried out. A total of 43 constituents were identified in the essential oil from fruits of Diphasia klaineana (FR) and the major compounds were β-elemol (30.23%), sabinene (9.28%), guaiol (5.12%), (E)-β-ocimene (5.11%) and δ-elemene (3.53%). The FR1 and FR3 fractions collected after one hour and after three hours were rich in hydrocarbon monoterpenes and showed bactericidal and bacteriostatic activities, respectively. No activity was found with FR5, FR7 and FR9 fractions. Therefore, fractional distillation may be an interesting process to upgrade the antibacterial activity of D. klaineana fruits essential oil againt Staphylococcus aureus.

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